/Engine/Plugins/Online/OnlineFramework/Source/Qos/Public/QosInterface.h
Get the subregion id for this instance, checking ini and commandline overrides This is only relevant for dedicated servers (so they can advertise). Client does not search on this (but may choose to prioritize results later)
static [FString](API\Runtime\Core\Containers\FString) GetAdvertisedSubregionId()